NLRP3炎症小体及相关信号通路介导钩端螺旋体感染性炎症反应机制研究

Leptospirosis is an important global zoonotic disease. After infection with leptospires, animals such as rats usually have no clinical symptoms and shed spirochetes from their urine for a long period of time, whereas all human individuals fall ill. Leptospira causes multi-organs (such as kidney, liver and lung) damages in severe cases. Previous studies showed that different inflammatory responses initiated by Leptospira were associated with tissue damages and pathogen clearance in human or animals, but the mechanism remains unknown. Recent reports found that NLRP3 inflammasome is closely related to the inflammatory response induced by pathogens in human or animals. In this research, we take the acting mechanisms of NLRP3 inflammasome and associated signaling pathways as the entry points to determine their diverse effectiveness and regulation mechanisms in inflammatory responses initiated by Leptospira infection in macrophages from human, rat and mouse by using ELISA, western blotting, flow cytometry, laser confocal microscopy, and multiple molecular biological techniques. The results of this study will contribute to elucidate pathogenic mechanism of Leptospira as well as provide novel ideas for prevention and therapy of leptospirosis, which refers to original findings with high academic value.

钩端螺旋体（简称钩体）病是全球流行的重要人兽共患病。钩体侵入鼠类等动物后常无症状且长期尿液排菌，人感染钩体后均发病，严重者可出现炎症性肝脏、肾脏等组织损伤。新近发现，钩体感染人和不同动物宿主后引起的炎症反应程度明显不同，炎症反应程度与组织损伤及病原体的清除密切相关，但其机制不明。近年发现NLRP3炎症小体与病原菌诱导宿主细胞产生炎症反应密切相关。本项目拟以NLRP3炎症小体及相关信号通路介导钩体感染性炎症反应机制为切入点，采用ELISA、Western blotting、流式细胞术、激光共聚焦及多种分子生物学技术，了解NLRP3炎症小体及其相关信号通路在钩体感染引起人、大鼠和小鼠巨噬细胞炎症反应中的作用及其调控机制，研究结果不仅有助于深入阐明钩体致病机制，也为钩体病防治提供新思路，具有较高创新性和学术价值。

钩端螺旋体（简称钩体）病是全球流行的重要人兽共患病。钩体侵入鼠类等动物后常无症状且长期尿液排菌，人感染钩体后均发病，严重者可出现炎症性肝脏、肾脏等组织损伤。新近发现，钩体感染人和不同动物宿主后引起的炎症反应程度明显不同，炎症反应程度与组织损伤及病原体的清除密切相关，但其机制不明。在国家自然科学基金的资助下，我们采用ELISA、Western blotting、流式细胞术、激光共聚焦及多种分子生物学技术研究了NLRP3炎症小体及其相关信号通路在钩体感染引起人、大鼠和小鼠巨噬细胞炎症反应中的作用及其调控机制。本项目研究结果发现，人和小鼠巨噬细胞感染钩体后NLRP3 炎症小体均发生活化并参与介导分泌炎性细胞因子，细胞因子分泌规律存在明显差异，人巨噬细胞感染钩体后IL-1β 和IL-18 的分泌早于小鼠巨噬细胞，且分泌水平较小鼠巨噬细胞更高。ROS和Cathepsin B途径参与活化NLRP3炎症小体后引起下游的炎性细胞因子IL-1β和IL-18的分泌。钩体感染过程中NF-κB、p38MAPK 和JNK 信号通路上调IL-1β、TNF-α和IL-6 炎性细胞因子的表达和分泌而放大炎症反应。研究结果为钩体感染人和宿主动物后起严重程度截然不同的脏器炎症性病变和损伤及其致病差异的科学解释提供了依据，不仅有助于深入阐明钩体致病机制，也可能为钩体病的防治提供新思路，具有较高创新性和学术价值。本研究共发表核心期刊论文9篇，其中SCI论文2篇，核心期刊论文7篇，另有1篇SCI论文已被录用待发表。本人受邀请在第十届国际钩体病学会学术会议上做了大会报告，培养硕士研究生2名。对照项目计划书，我们已按期完成了项目的研究任务并达到了考核要求。